Dresden 2006 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 13: Spin controlled transport I
HL 13.9: Vortrag
Dienstag, 28. März 2006, 13:00–13:15, BEY 118
Magnetic anisotropy and antiferromagnetic exchange of Co impurities in ZnO — •Roland Hayn1, Pascal Sati1, Anatole Stepanov1, Roman Kuzian2, Thomas Chanier1, Steffen Schäfer1, Sonia Régnier1, and Christian Morhain3 — 1Laboratoire Materiaux et Microelectronique de Provence, 13397, Marseille Cedex 20, France — 2Institute for Material Science, Krzhizhanovskogo 3, 03180 Kiev, Ukraine — 3Centre de Recherche sur l’Hetero-Epitaxie et ses Applications-CNRS, 06560, Valbonne Sophia-Antipolis, France
We report on the magnetic properties of (Zn,Co)O epitaxial thin films with low Co concentration. Magnetic and EPR measurements, combined with crystal field theory, reveal that isolated Co impurities possess a strong single ion anisotropy, which would lead to an easy plane ferromagnetic state when a hypothetical Co-Co interaction would be considered. However, the magnetization measurements show the presence of short-range antiferromagnetic exchange interactions between nearest-neighbor magnetic ions which is supported by LSDA+U calculations.